Coded document

ABSTRACT

A Touch-tone coded credit card employing first and second code groups, the first group having four bit positions and the second group three bit positions, one of which is utilized in each group to identify a decimal digit. The card is provided with a noncoded area (used for a magnetic or signature stripe) which is positioned opposite the first code group, and is at least as wide. If the card is reversed side-to-side when positioned in a code reader, no output is derived from the first code group because the reader scans the non-coded area. This fact can be employed to prevent faulty operation of the card reading system.

United States Patent 1 Zucker [451 May 1, 1973 CODED DOCUMENT [75]Inventor: Fredric E. Zucker, Stamford, Conn.

[73] Assignee: Pitney-Bowes, lnc., Stamford,

Conn.

[22] Filed: Oct. 8, 1970 21 Appl. No.: 79,193

[52] U.S. C1....235/6l.12 N, 179/6.3 CC, 340/149 A,

235/61.l2 R, 61.12 N, 61.7 B, 61.11 E; 340/149 A; 250/219 DC 3,543,00711/1970 Brinker ..235/61.11 E 3,394,246 7/1968 Goldman ..235/61.7 B

3,320,369 5/1967 Hershey l ..179/90 CL 3,474,230 10/1969 McMillen..235/61.7 R

Primary ExaminerMaynard R. Wilbur Assistant Examiner-Robert M. KilgoreAtmmeyWil1iam D. Soltow, Jr., Albert W. Scribner, Martin D. Wittsteinand Louis A. Tirelli [57] ABSTRACT A Touch-tone coded credit cardemploying first and second code groups, the first group having four bitpositions and the second group three bit positions, one of which isutilized in each group to identify a decimal digit. The card is providedwith a non-coded area (used for a magnetic or signature stripe) which isposi- [56] References Cited tioned opposite the first code group, and 18at least as UNITED STATES PATENTS wide. If the card is reversedside-to-side when positioned in a code reader, no output is derived fromthe 3,444,517 5/1969 Rabmow ..340/l46.3 3 529 133 9 first code groupbecause the reader scans the non- /1970 Kent ...235/61.11 E 3,184,7145/1965 Brown "340/149 A coded area. This fact can be employed to preventfaul- 3,s13,441 5 1970 Schwend ..235/6l.7 B ty Operaflon Of h Cardfeadmg y 3,527,927 9/1965 Bijleveld ..235/61.ll E 3,573,436 4/1971Berler ..235/61.ll E 1 Clam, 3 Drawmg Flgules 3,502,851 3/1970 Kakimoto..235/61.l2 R

NON CODED AREA !6 O O O '5 G GROUPA 2,;

15 t O O O 0 o 0 GROUPB 7 COO comm DOCUMENT FIELD'OF THE INVENTION Thisinvention relates generally to machine-readable documents, andparticularly to a credit card which is coded for use in a reading andverifying device, and designated to prevent improper reading of the cardwhen it is inadvertently reversed in the device.

BACKGROUND OF THE INVENTION A prominent feature of the economy in recentyears has been the use of credit cards, bank drafts, checks, and othersubstitutes for cash. This has led to some abuses, particularly in thecredit card field, where use of cards that are outdated, cancelled,lost, stolen, or even spurious has made some form of card verificationhigh desirable. Some business establishments maintain and check lists ofbad accounts, while others manually telephone a central information bankfor verification. Both procedures are expensive, time consuming,errorprone and inconvenient. The most reliable and efficient method ofverification employs an automatic system incorporating a device whichreads the card automatically, and transmits information automaticallyover telephone lines to a computer-operated central station.

This invention is intended for use in such a system, as well as in otherdocument-reading applications; and is directed to the problem ofproviding information on the card or other document which can be easilyread and transmitted by an automatic reading machine, and which will notproduce a faulty transmission even if the document is improperly placedin the reader.

SUMMARY OF THE INVENTION In one illustrative embodiment of theinvention, a coded credit card, bank check or other document for use inan automatic reading system has a plurality of code groups thereon, eachof which furnishes atleast one information bit for coding a givenalphanumeric character. The document also has a non-coded area which islocated opposite to, and is at least as wide as, one of the code groups;so that inverted positioning of the document in a reader, or any otherimproper place ment, produces no response from at least one code group,a fact which can be used to prevent faulty opera tion of the system inwhich the document is employed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary view of acoded credit card in accordance with the present invention.

FIG. 2 shows a push-button telephone keyboard, and I DETAILEDDESCRIPTION OF THE PREFERRED EMBODIMENT The particular coded documentwhich will be described herein is a machine-readable plastic credit card(generally designated 10), but it will be apparent that the principlesof this invention are applicable to other types of documents anddocument-reading systems. The credit card has a plurality ofphotoelectrically readable spots forming coded alphanumeric characterrepresentations 12 thereon. The spots are arranged in code groups A andB. Groups A of all the characters 12 are aligned in the center of thecard, and groups B are aligned along one edge 10a. The locations of onlythree coded characters 12.1 through 12.3 are indicated explicitly; butroom exists on a standard-sized credit card (3 X 2 Vs inches) for aconsiderably greater number of such characters.

Along edge 10b of the card, opposite code group B, the card 10 has anarea 16 which is devoid of photoelectrically machine-readable markingsdescribed above. The area could be occupied by a signature stripe. Mostsuch cards are made of plastic materials such as polyvinyl chloride,which are not receptive to ink. Therefore a strip of paper or otherink-receptive material is often secured to the card to receive thewritten signature of the card subscriber (for comparison with asignature written at the time a sale is consummated). Alternatively,area 16 could be occupied by a magnetic code strip, to make the cardreadable by magnetic as well as photo-electric equipment.

Each code group A and B of each character 12 has a plurality of bitpositions 15, some of which are imprinted with data bits, i.e.,photo-electrically readable spots 15a. The latter are preferablyimprinted with a luminescent marker material which is invisible undernormal illumination, making it more difficult to tamper with the card.The marker material is readable photoelectrically, however, underultra-violet illumination.

Other machine-readable bit-marking materials are also comtemplated; suchas magnetic spots, conductive ink, ordinary ink, etc., for reading bymagnetic, photoelectric, or any equivalent means. Whatevermachinereadable format is selected for code groups A and B, however, thestripe 16 must be devoid of any information in that same format, but itmay contain information in any other machine-readable format. If thecode groups A and B are coded in a luminescent format, for example, thestripe 16 can contain a signature, but not one which is written inluminescent ink. Or if the code groups are in a conventional (i.e.non-luminescent) photo-electrically readable format, the stripe 16should be of uniform appearance, devoid of any signature, but it maycontain mangetically coded data. If the code groups are in a magneticformat, on the other hand, the stripe 16 may not be magnetically coded,but it may contain a signature written with luminescent material or anyother kind of non-magnetic ink.

In these drawings, incidentally, the lines seen on credit card 10 areimaginary ones employed only for illustrative purposes, to delineate thecharacter areas 12 and their code groups A and B. Such lines do notnormally appear on an actual credit card.

In order to facilitate transmission of information from the credit cardreader over telephone lines to a computer-operated verifying station,the preferred code format is the two-frequency-tone push-buttontelephone code known as Touch-tone in the Bell Systems terminology. Inthis code each character is represented by a particular combination .oftwo frequency tones. One frequency, fA, is selected from a group of fourtones fAl through fA4; and the other frequency,jB, is selected from agroup of three tones, fBl through fB3. The exact encoding scheme fordecimal characters 1 through is illustrated by the push-button telephonekeyboard in FIG. 2.

On the credit card 10, only one of the four bit positions in group A isselected to represent the particular frequency fA, and only one of thethree bit positions in group B is selected to represent the particularfrequencyfB. In character area 12.3 of FIG. 1, for example, luminescentspots 15a occur in the second position of group A and the first positionof group B, uniquely representing the decimal digit 4" in Touch-tonecode. This code formal is employed for each character 12 across the card10, to provide the plurality of digits which identify a particularcredit card holder. The selected spots 15a of each character thusdesignate the particular two frequencies which represent each character.It will be readily apparent to those skilled in the art, however, thatother plural-group code formats may be utilized.

To illustrate the use of the coded card in a verification system,reference is made to FIG. 3. The card is inserted (as indicated by arrow17) into any suitable reader 18 which then scans the card (either in thedirection of arrow 17 or the opposite direction) so that the spots a ofsuccessive character areas 12 can be read. If the luminescent approachis employed, the reader 18 will employ an ultra-violet source toilluminate the spots, and seven separate photocell channels for scanningeach of the four bit positions in code group A and the three in group Brespectively. Regardless of the particular sensing technique, however,two distinct code group reading operations occur simultaneously forgroups A and B respectively. At the output of the reader 18, therefore,one of fourfA output lines will be energized, designating a particularfrequencyfA, while one of threefB output lines will be energized,designating a particular frequency fB. The fA output in effectrepresents the reading of a four channel code group; while thefB outputrepresents the reading of an entirely separate three channel code group.

Both outputsfA andfB are applied to a conventional telephone encoder 20which responds by generating a signal combining the selected frequencytones fA plus jB to represent a single character in a particular area12. The output of the encoder is fed over a suitable telephone or othertransmission line 22 to a computeroperated central station 24.

Suppose, however, that the credit card 10 is improperly inserted intothe code reader. For example, it may be flipped over on its reverseside. In that case, the reader 18 will not sense a luminescent bit ineither code group A or B, because there are no luminescent markings onthe reverse side. The total absence of any fA orfB output can easily berecognized electronically as an error condition.

Alternatively, the card may be inverted side-for-side, so that non-codedarea 16 is positioned in the reader 18 where code group B ought to be.When this happens, if area 16 is at least as wide as code group B, noluminescent bits 15a of code group A can be read by the photocells ofgroup B. Therefore, the reader 18 will provide no output at all on thefB side, which is also recognizable electronically as an errorcondition.

There will be an output on thefA side, but the fact that code group B isread independently from group A enables it to stand alone as an errorindicator under these circumstances. Accordingly, the credit card 10provides a foolproof scheme for detecting any type of improper insertioninto the reader 18.

To summarize and generalize the principle exemplified by the particularcredit card described, any machine-readable document using any pluralgroup code format may be similarly protected against side-tosidereversal within a reader device; provided there are at least twoindependently read areas (so that the absence of an output from only oneparticular area is readily detectable), and if the document surface areadevoted to that particular information group is paired with another areadevoid of machine-readable inform ation, in such a way that documentreversal will necessarily produce that no-output condition. Placement ofthe two areas on opposite edges of the document (as described above) isone example of such pairing; but any other arrangement would also workin which the non-machine readable area is either congruent with itspaired machine-readable area, or encloses a portion which can beregarded as congruent therewith, and at least the congruent portion ofthe non-machineablereadable area is situated symmetrically with themachine-readable area relative to the document center line. Thoseconditions guarantee an exact exchange of positions when the document isreversed in a side-byside sense.

Since the foregoing description and drawings are merely illustrative,the scope of protection ofthe invention has been more broadly stated inthe following claims; and these should be liberally interpreted so as toobtain the benefits of all equivalents to which the invention is fairlyentitled.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A substantially rectangular document bearing information encoded in amachine-readable format including a plurality of code groups each ofwhich furnishes at least one essential bit of information for each codedcharacter; said document comprising on at least one face thereof:

a. a first area adjacent a first edge of said document and bearing afirst one of said code groups;

b. a second area adjacent said first area and bearing the remainder ofsaid code groups;

c. and a third area adjacent an edge of said document opposite saidfirst edge, said third area being at least as large as said first areain a direction transverse to said edges whereby incorrect positioning ofsaid document in a reader device interposes said third area in theportion of said reader which is designed to read first area, and saidthird area is devoid of code bits of said format whereby the absence ofan output derived from said first area provided an indication of theincorrect positioning of said document in said reader; there being atleast first and second code groups,

the first code group having at least three bit positions and the secondcode group having at least four bit positions, and said code formatemploying at least one photo-electrically readable bit in each group;

said non-coded third area being contiguous to said second code grouparea;

said bits employed in said first and second code groups being imprintedwith luminescent material; and 5 said document being a non-ink-receptivecard and said non-coded third area being covered withan ink-receptivematerial to carry a signature.

1. A substantially rectangular document bearing information encoded in amachine-readable format including a plurality of code groups each ofwhich furnishes at least one essential bit of information for each codedcharacter; said document comprising on at least one face thereof: a. afirst area adjacent a first edge of said document and bearing a firstone of said code groups; b. a second area adjacent said first area andbearing the remainder of said code groups; c. and a third area adjacentan edge of said document opposite said first edge, said third area beingat least as large as said first area in a direction transverse to saidedges whereby incorrect positioning of said document in a reader deviceinterposes said third area in the portion of said reader which isdesigned to read first area, and said third area is devoid of code bitsof said format whereby the absence of an output derived from said firstarea provided an indication of the incorrect positioning of saiddocument in said reader; there being at least first and second codegroups, the first code group having at least three bit positions and thesecond code group having at least four bit positions, and said codeformat employing at least one photo-electrically readable bit in eachgroup; said non-coded third area being contiguous to said second codegroup area; said bits employed in said first and second code groupsbeing imprinted with luminescent material; and said document being anon-ink-receptive card and said non-coded third area being covered withan ink-receptive material to carry a signature.